I. Field of the Invention
The present invention relates to gaging. More particularly, the present invention relates to gaging the hexagonally shaped heads of fasteners.
II. Description of the Prior Art
Manufacturers have long sought suitable gaging devices to quickly determine the size of a fastener. Fasteners conform to standard dimensional specifications which can be readily ascertained by reference to tables of bolt and nut data in engineering source books. By using the information provided in the reference tables, if the width across flats of a hex head fastener can be determined, then other dimensional data can be assumed.
Since the early days of manufacturing and assembly, a steel rule has been used for placing across the head of the item for which more dimensional information is sought. In lieu of the extremely simple steel rule, Calipers or any other of a number of measuring devices can be used. However, these are all awkward to use. Clearly, these type of devices are valuable only in a limited number of circumstances, such as when measuring a single item.
In an effort to overcome the problems of known hex head fastener gaging, several modifications have been attempted.
A metric gage is described in U.S. Pat. No. 4,138,820 to O'Connor. This gage uses measuring sockets to gage sizes of components of nuts and bolts. This metric gage also has circular portions to gage the diameter of bolts and cylindrical means to gage nut size. The cylindrical means extends from the circular means.
A problem can arise in assembly operations when various types of fasteners are used in close proximity to one another. The problem is particularly acute when metric series sized fasteners become mixed with English, also known as United States, or inch sized fasteners. To the naked eye, some sizes of English/United States or inch designated fasteners are dimensionally close to metric series sized fasteners. If a metric series fastener that is dimensionally close to a English or United States series sized fastener should be substituted, the proper bolt holding torque cannot be applied to the bolt to hold it to the mating threads, thereby creating a potential safety, warranty or liability problem.
In the past, when a mixed load of fasteners has been found, it has been a tedious job to sort through the bolts and separate them for size as well as English or United States inch or metric series.
While providing some degree of ease in measuring hex head fasteners, all the known art suffers from a common defect, the lack of a quick method for measuring mixed loads of fastener hex heads comprising sizes in metric system series which are given in millimeters or English/United States system sizes of measurement which are given in units.